Filter press



Nov. 24, 1.931.

M. WILDERMAN FILTER PRESS 2 Sheets-Sheet Filed oct. 2e, 1929 INVE NTOR Nov. 24, 1931. M. wlLDERMAN FILTER PRESS I 2 Sheets-Sheet 2 Filed Oct. 26. 1929 INVENToR Patented N0v.i2`4, i931 UNITED STATES- PATENT oFi-icE MEYER WILDERMAN, OF HAMPSTEAD, LONDON, ENGLAND, .ASSIGNOR TO THE .AMERICAN WILDERMAN POROUS EBONITE COMPANY, INC., OF PHILADELPHIA,

PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA FILTER PRESS Application filed. October 26, 1929, Serial No. 402,696, and in Great Britain lNovember 10, 1927.

This invention relates to filter presses, and more particularly toilter presses containing a series of double filters, each double filter consisting of two single filter plates provided .at the present time consist of a series of solid metal or wooden plates having projections or ribs thereon which support a filtering medium such as filter cloth. In theA filtering process the filtrate flows through the filtering medium into the channels formed by the projections on the plates and thence to the exit of the press. i i

This type of filter ress has several disadvantages among which may be mentioned, first, during the filtering operation the filter cloth sags between the supporting projections or ribs, tending to tear the cloth and also decreasing the speed of filtration; second, the ribs or projections on the solid plate which support the filter cloth decrease the effective filtering surface of the filter; third the materials of which the plates are made will not withstand the action of certain chemicals, so that it is necessary in different processes to select materials suitable to the solutions which are being filtered.

In accordance with my invention I provide a series of double filters, -each*double filter containing two single filters with individual rims which provide spaces within the double filters for the filtrate and spaces between the double filters for the residue. The preferred material of which the filter plates are made is porous ebonite. The plates may be made in accordance with the process described in my Patent No. 1,651,567, granted December 6, 1927.

In the accompanying drawings two present preferred forms of my invention are given by way of illustration. ,I j

Figures 1 to 4 are diagrammatic crosssectional views showing the assemblage of filter plates in a filter press. Figures 1 and 2 illustrate an embodiment in which the main body of the plates is made of porous ebonite and the rims are made of non-porous ebonite. Figs. 3 and 4 illustrate an embodiment in which the main body of the fplates is formed of perforated metal plates having wire gauze and filter cloth secured thereto,

Fig. 5 is a plan view of a single filter plate, two lof these single filter plates lforming a double filter plate having a space within for the filtrate,

Figure 6 is a horizontal section on the line VI--VI of Fig. 5, i

Fi re 7 is a vertical section on the line VII- VII of Fig. 5,

. Figure 8 is a horizontal section of a double lter plate taken on a line corresponding to the line VIII-VIII of Fig. 5,

Figure 9 is a vertical sectional. view through a lter press illustrating the filteringroperation, and

igure 1,0 is a view similar to Fig. 9 illustrating the washing operation.

Figure 11 is a detailed view on an enlarged clztile, showing the shape of the ribs on the Referring to the embodiment shown in Fig. 1, the filter press comprises a series of double -filters l2, each double lilte` consisting of two single filter plates 3. The main'body of the single filter plates 3 is made of porous ebonite,v butthe rimsllare made of non-porous ebonite. The rims 4 are recessed as indicated at 6 so that when two single filter plates 3 are assembled they provide a space 7 within each double filter for the filtrate and a space 8 between adjacent double filters for the residue.

The embodiment illustrated in Fig. 2 is vsimilar to the embodiment of Fig. 1 except that instead of forming recesses in the rims, separating frames 9 are employed between the double filters 2a, and separating frames `1() are employed between the single filter plates` 3a. As inthe embodiment shown` in Fig. 1

In the embodiment illustrated in Fig. 3 the double filters each consist of two single filter plates 3b. The body of the lates is perforated and both the body and rim 4b are metal. A gauze filtering screen 11, indicated by the heavy line, and a filter cloth 12 indicated by the light line, are secured to the filtering surfaces of the plates 3b. The rims 4* are recessed in a manner similar to that described in connection` with the embodiment shown in Fig. 1. l

In the embodiment illustrated in Fig. 4, perforated metal plates 3" covered with a gauze filtering screen 11, indicated by the heavy line, and filter cloth 12, indicated by the light line are employed. The double filters are separated by rims 9c. The frames 4 of the single filter plates 3 are recessed as indicated at 6. When the filter plates are assembled in the press they provide spaces 7 within the double filters 2c and spaces 8c between the double filters.

In cases where perforated metal plates are used, both the rim and body portions may be covered with a thin layer of non-porous ebonite in order to protect the plates from the action of such chemicals as would attack them. U

Referring to Figs. 5 to 8, inclusive` each single filter plate -3 comprises a rim 4 o nonporous ebonite and a main body portionpf porous ebonite. The rim 4 is provided with an o ening 15 which forms an inlet for the solutlon to be filtered, an opening 16 which forms an outlet for the filtrate, an opening 17 forming an inlet for wash water, and anopening 18 forming an outlet for the wash water.

In order to. aid the filtering process the openings 15 and 17 may beconnected to a source of pressure and the openings 16 and 18 to a source of suction. 4The filter plate has horizontal ribs 19 of non-porous ebonite and vertical ribs 20 of metal covered with nonporous ebonite which form a grid which supports the orous ebonite filtering medium.

`Prefe'ra ly the horizontal ribs 19 and the vertical ribs 20 are chosen of such a section that the apertures formed by them represent a double cone (see Figure 11) the two wider bases of the double cone of each a erture .being turned to the two outer sides o the porous filter, the object being to increase the surface of filtration, to create a larger surface of combination between the porous filter within the aperture and the non-porous ebonite of the grid, and to support the porous filters against pressure during filtration or washing of the cake.

As shown in Fi s. 5, 7 and 8, the horizontal ribs 19 are embe ded in the porous ebonite filtering medium, but the vertical vribs 20 extend beyond the orous ebonite into the s ace between the dou le filters. Portions o the ribs 20 adjacent their ends are cut out as indicated at 21 (Figures 5 and 7) to provide Spaces for the free fiow of solution to the' openings 15, 16, 17 and 18. The grooves are filled by gaskets 23 which insure a tight joint between the filter plates when they are assembled in the filter press.

Figure 9' illustrates the filtering process. The solution to be filtered flows through the opening 15, through the openings 25 leading to the spacesl8 between the double filters. The filtrate passes through the single filter plates into the spaces 7 within the double filters and from there passes into the outlet passage 16.

In the washing operation, the washwater enters through the passage 17 and fiows through openings 26 into alternate spaces 7 within alternate double filters. From the spaces 7 the wash water flows in opposite directions, as indicated by the arrows, through the cake or residue contained in the spaces 8 between adjacent double filters, and then through the single filter plates to the spaces 7 within the double filters. From the spaces 7 the wash water flows through passages 27 into the outlet passage 18.

Instead of making the rim and grid of nonporous ebonite, they may be made of metal covered with non-porous ebonite. I

In ordinary practice, when porous ebonite lter plates are employed it is unnecessary to use filter cloth, but if desired in order to prevent the precipitate from contacting with the porous ebonite or to facilitate the removal of the recipitate from the press, thin filter cloth, lter paper et cetera may be usefully employed.-

I have illustrated and described several preferred forms of my invention. It is to be understood, however, that the invention is' not restricted to these and may be otherwise embodied within the scope of the following claims.

I claim:

1. A filter press comprising double filter plates, each double filter containing single filter plates with individual rims providing a space within the double filter plates for the filtrate, in which the single filter plates of the double filter are provided with ribs which strengthen them, the ribs projecting into the spaces within thedouble filter and contacting with ribs on the opposite plate of the double filter in order to support the single plates against the pressure of the -solution being filtered.

2. A filter press provided with inlet and outlet openings, confliprising ter-p a vidlng a space within the double filter p sesam of being cut away in order to allow free ow of solution to the inlet and outlet openings.

3. A filter press comprising double filter plates,- each double filter plate containing single filter plateswith individual rims providm a` space within the double filter plates for t e filtrate, in which the single lter plate consists of grids formed of cross memrs connected at their ends to the rim, the

rim and cross members being made of metal' covered with a non-porous substance, the spaces between the cross members containing a porous lterin medium, the rim and cross members and tering medium forming a unitary structure.

tered.

double filter with ribs on the opposite plate of the double ate containing lter in order to support the single lates inst the pressure of the solution ins In testimony whereof I have hereunto set my hand.

4. A filter press comprising double filter plates each double ilter late containing singlelterplates with indil'idual rims rovidm a s ace within the double'iilter p ates for t e tratev in which the single filter lates consist of rs connected at their ends to the rim, the rim and cross members being made of metal covered with non-porous ebonite, the spaces between the cross members containing orous ebonite, the frame and cross mem rs and porous ebonite forming a unitary structure.

5. A filter ress comprising double filter plates, each ouble filter 'plate containing single filter plates with individual rims rovi a space within the double lilter p ates for e filtrate in which the single filter pistes consist of grids formed of cross mem-l rs connected at their ends to the rim, the rim and some lof the cross members being made of metal covered with non-porous ebonite, while the rest'of the cross members is made of non-porous ebonite, the spaces between the cross members containing porous ebonite, the rim and .cross members and lporous ebonite forming a unita structure.

6. A filter press comprising oublelter plates, each double lter containing single ter plates with individual rims provi a space within the double filter plates for the filtrate, in which each of the single filter plates of the double filter is composed of a perforated metal late having ilte means supported t ereon, the perfora metal plates having ribs rojecting into the space within the double ter and contacting grids formed of cross mem- MEYER WILDERMAN. 

